Add HtmlHelper.FileFor

After not finding one, I created a HtmlHelper for <input type=file /> elements. I basically decompiled the MVC code and then made some alterations here and there.

It's working for my needs. It creates the right field names for post back and binding and also adds appropriate validation.

Is there interest in adding this to the framework? I can work on preparing a PR, but didn't want to spend too much time if it was purposely left out. Maybe there are tricky edge cases I'm not thinking of? Or maybe it just wasn't a high priority?

That does sound like a cool idea. Can you log an issue in the issue tracker so that the bug/issue triage team can make a call on it? It would be helpful if you include information on why it would be useful.